Bilateral Renal Stones Associated with Nail-Patella Syndrome

Dr. Sanjiv Saxena, Assistant Professor, Department of Nephrology, AIIMS, New Delhi-110029 (India) Dear Sir, The nail-patella syndrome (hereditary osteo-onychodysplasia or HOOD) is a well-recognized autosomal dominant disorder characterized by nail, skeletal and renal abnormalities. A spectrum of renal involvement has been described in patients with the nail-patella syndrome [1,2]. Although Glassock et al. [3] mention that a disproportionate number of these patients may have renal stones (references not quoted), on review of the literature, we came across only three case reports describing such an association [2, 4, 5]. However, all the above three cases had evidence of unilateral calculus disease. A 23-year-old male was referred to the Nephrology Services of All India Institute of Medical Sciences, New Delhi in June 1993 for the management of chronic renal failure. He had a history of recurrent bilateral renal colics for the preceeding 3 years and had undergone pyelolithotomy on the right side and ureteroli-thotomy on the left side for bilateral calculus disease 2 years earlier in a district hospital. The status of his renal functions at the time of surgery was not known. The patient had no subsequent colics and repeated skiagrams revealed no radiopaque calculi. However, for the preceding 4 months, he started having anasarca and was found to have mild hypertension and moderately severe azotemia. There was no history of renal calculus disease or any other renal illness in the family. Clinical examination revealed severe pallor, mild hypertension and changes of chronic azotemia. In addition, the patient had dystro-phic nails in both upper and lower limbs, fixed flexion deformity of the right elbow, bilaterally small hypoplastic patellae and bilaterally palpable iliac horns. There were surgical scars of pyelolithotomy and ureteroli-thotomy on the right side and left side of the abdomen, respectively. Neither of the kidneys was palpable. Laboratory evaluation confirmed the presence of severe anemia with Hb 0.70 mmol/l (4.7g/dl) and severe azotemia with serum cre-atinine of 1,408 μmol/l (16.0 mg/dl). Urine examination revealed 2+proteinuria and 8-10 WBCs per high power field on microscopy. 24-hour urine examination showed 1.98g proteinuria and a creatinine clearance of 4 ml/ min. Skeletal survey revealed bilateral iliac horns, bilaterally hypoplastic patellae and an ill-developed capitellum of right radius. Ultra-sonography of the abdomen revealed bilateral normal-sized kidneys with a